How to make faceless sphere
bmesh script.

Add sphere, remove only faces with bmesh in object mode

import bpy
import bmesh

context = bpy.context

bpy.ops.mesh.primitive_uv_sphere_add()
ob = context.object
me = ob.data
bm = bmesh.new()
bm.from_mesh(me)
bmesh.ops.delete(bm, geom=bm.faces, context='FACES_ONLY')
bm.to_mesh(me)
me.update()